DE102005025247B3 - Method for manufacturing through hole in thermo plastic component, involves two-dimensional application of first thermo plastic plate with first softening temperature on substrate plate - Google Patents

Abstract

Method involves two-dimensional application of first thermo plastic plate (1) with a first softening temperature on a substrate plate (2). A tool is pressed into first thermoplastic plate with a temperature above T1, whereby plate structures (6) are formed with structure heights H1. The application of thermoplastic workpiece (8) is done with second softening temperature less than T1 with thickness lesser than H1 on structure cooled below temperature T2.

Description

The The invention relates to a method for producing through-openings in thermoplastic components according to the features of the first Claim.

Through openings such as holes, recesses or other breakthroughs in thermoplastic Components of small dimensions are usually already included provided for the preparation, for example via an impression accordingly designed negative forms during an injection molding process.

alternative are processes known in which through holes in thermoplastic components also later by drilling, punching, punching or pushing out be manufactured by component parts at predetermined breaking points. For an economic subsequent Create a larger number of passage openings in unstructured thermoplastic components of small dimensions Punching and punching methods are particularly suitable.

In the DE 197 30 859 A1 For example, a punching method and a device for punching workpieces made of a thermoplastic material are described. The hole tool comprises a punch, which is pressed by the workpiece in a form-fitting manner in a bore in a cutting plate, wherein a workpiece segment between the punch and hole edge is sheared off to form a through hole in the workpiece. Important in this device is therefore an exact axial guidance of the punch before and when penetrating into the hole, in the proposed solution by a laterally to the punch arranged separate pin guide and by guiding the punch in a guide bore before the penetration into the workpiece is realized.

Furthermore, in the DE 199 31 774 A1 as part of a process alternative to increase the precision of the production of a cutting plate for a micro-punching device by galvanic molding a punch revealed.

The aforementioned solution is not or only limited to punching or punching transferable in microsystem technology. In particular, the disclosed punch guides let see with the required guidance accuracies only limited or scale down with an increased effort.

From that Based on the object of the invention is a specially designed for microsystems technology Punching process for the production of through holes in thermoplastic To propose components.

The The object is achieved by a method according to the features of the first Patent claim solved. Subordinate claims advantageous embodiments again.

The Invention is as follows in the context of embodiments with figures explained in more detail. It demonstrate

1a to g in a schematic representation of the individual process steps of the aforementioned method and

2a and b design options for other embodiments.

The method is used to produce through holes in thermoplastic components. In a first method step, this is a first plate 1 made of a thermoplastic material flat on a substrate plate 2 hung up ( 1a ). This first plate, preferably made of a synthetic material, has a first softening temperature T1. In a second step, an indentation of a stamped with a temperature above T1 embossing tool 3 with stamps 17 in the first thermoplastic plate 1 represented in 1b with an arrow for the push-in movement 4 , Through the sen Heißprägenvorgang be through the stamp 17 in the first plate 1 structures 6 imprinted with preferably a structural height H1. During or before lifting the embossing tool from the structure 6 as part of a third process step (Hub 5 as an arrow in 1c ), the first plate is cooled 1 with the structures 6 below the softening temperature T1. In a fourth method step, a flat insert takes place (see insertion movement 7 as an arrow in 1d ) a thermoplastic component 8th or a component segment (hereinafter referred to as containing component) having a second softening temperature T2 which is below the first softening temperature T1. It follows in a fifth step, a new impressions (see 4 in 1e ) of the tempered with a temperature between T1 and T2 embossing tool 3 through the component into the structures 6 , where punched parts as workpiece segments 9 the component 8th with the embossing tool 3 are pressed into the recesses of the structures ( 1e ). Here for it is necessary that the component 8th , at least the areas of the component that are on the embossed structures 6 are positioned and through the process with a through hole 10 (see. 1f ), a thickness D2 (cf. 1d ) smaller than the structure height H1 of the previously cooled under T2 structure. In a further process step then take off (Hub 5 ) of the embossing tool and the removal (removal movement 11 ) of the broken component ( 1f ).

The method thus provides a combination of a hot embossing method in which the aforementioned first plate 1 by pressing in the heated punching tool 3 a negative form with the above-mentioned structures 6 is produced as a cutting plate, and from a subsequent punching process in which the punching tool is pressed by the applied to the cutting plate component again and positively in the negative mold in an insert, wherein one or more workpiece segments 9 between punching tool and opposite structural edges to form through holes 10 in the workpiece 8th is sheared off. The punching tool and the cutting plate are linear to each other and guided in alignment of the punch, the entire implementation of the method in a clamping, ie without conversion of punch and first plate or cutting plate.

In particular, material or component testing machines (eg spindle-driven, servohydraulic, etc.), mechanical or hydraulic presses or devices (eg lever presses), modified embossing and punching machines) or other machines are apparatuses and devices which provide the aforementioned exact guidance ensure punching tool and cutting plate. Preferably, the device comprises a guide for the workpiece and means for reproducibly adjusting the height of the stroke 5 and the pushing-in movement 4 ,

Of the Advantage of this aforementioned combined method is that by hot stamping the the aforementioned insert is created, which then without retooling the Punching device precisely aligned for the subsequent punching process is used, and without loss of accuracy also for the Creation of complex passage opening patterns (hole patterns) and / or small dimensions. Warming up during the Punching causes advantageously a selective weakening of the Workpiece material during the Shearing the workpiece segments.

Without a renewed hot embossing process, the cutting plate (structured first plate) can be used for a plurality of successive punching operations, each using a different workpiece at each repetition, wherein each punching operation requires removal of the punched workpiece segments from the structure (cf. 1g ).

• – Einerseits bietet es sich an, gezielt eine formschlüssige Verbindung im Bereich zwischen Stanzwerkzeug und Werkstücksegment vorzusehen, die ein Anhaften und Herausziehen der Werkstücksegmente mit dem Stanzwerkzeug ermöglicht. Durch ein erneutes Aufheizen des herausgezogenen Stanzwerkzeuges auf eine Temperatur oberhalb T2 lassen sich die Werkstücksegmente auf einfache Weise z.B. mit einem Abstreifer auf einfache Weise wieder entfernen.
• – Ausblasen der Schneidplatte mit Druckluft
• – Einlegen einer Zwischenschicht sowie Aufschmelzen oder Verschmelzen dieser Schicht mit den Werkstücksegmenten in der Schneidplatte mit anschließenden Entfernen Zwischenschicht mit den anhaftenden Werkstücksegmenten

A removal of the punched workpiece segments 9 from the structures 6 , in 1g with an ejection movement 12 symbolic arrow is possible in several ways:

• On the one hand, it makes sense to specifically provide a positive connection in the area between the punching tool and the workpiece segment, which makes it possible to adhere and extract the workpiece segments with the punching tool. By re-heating the punching tool pulled out to a temperature above T2, the workpiece segments can be removed in a simple manner, for example, with a scraper in a simple manner again.
• - Blowing out the cutting plate with compressed air
• - Inserting an intermediate layer and melting or fusing this layer with the workpiece segments in the cutting plate with subsequent removal of the intermediate layer with the adhering workpiece segments

One good punching result, especially at an aforementioned repetition the punching operations with the same cutting tool, is directly dependent on the material properties the cutting plate. In particular, a high dimensional stability in the Softening temperature T2 to ensure the punching component (workpiece). With an increasing number of repetitions also wins the wear resistance at T2 increasingly important. In these framework conditions proved certain thermoplastics suitable. preferred Material pairings for the workpiece and the thermoplastic plate (insert) are on the one hand Polycarbonate (PC), polysulfone (PSU), polymethyl methacrylate (PMMA), Cycloolefin copolymer (COC) or polyoxymethylene (POM) for the workpiece as well PSU for the first plate and on the other hand PSU, PC, PMMA or COC for the workpiece as well Polyetheretherketone (PEEK) or Liquid Crystalline Polymers (LCP) for the first plate. LCP and PEEK are hard, brittle and high temperature resistant to it particularly dimensionally stable and particularly suitable as an insert. PSU is also comparatively temperature resistant, though not like LCP and PEEK, but in comparison to these ductile and not so brittle. It is therefore also suitable as an insert. Basically suitable although not so good due to the material properties, but also PC and COC as snowflake material.

2a and b give design options for other embodiments again. Both figures represent a process state corresponding to 1a ie before impressing structures into the first plate. In order to improve the stability of the cutting plate (structured first plate) also for the aforementioned multiple successive punching operations, it is advantageous to the first plate in the unstructured areas with insertion structures 13 to reinforce, and this particular in the context of a series production of the tool 3 and the embossed structures 6 is customizable (Cf. 2a ). Preferably, these Einlegstrukturen are made of a durable material such as a metal. As a result, an existing in principle in a thermoplastic material of the first plate flow tendency is significantly impeded and thus improves the dimensional stability of the insert advantageously. Alternatively or additionally, yielding of the structured first plate by flow or other plastic deformation is also achieved by a stiff ring tension anchor 14 as frame for the plate overall reducible (see. 2 B ).

2 B are also embodiments for a simplified removal of the punched workpiece segments in an ejection movement again (see. 1g ). Hollow punches, preferably heated, realized by bores 15 in the stamp 17 the punching tool, allow suction of punched workpiece segments, which still have plastic properties by heating to the softening temperature T2 or above. Alternatively, can be through recesses 16 in the substrate plate 2 attach pneumatic or mechanical ejection mechanisms for the ejection movement from below to the first plate, wherein the placement of the recesses on the substrate plate preferably to the punch positions on the tool 3 are aligned (cf. 2 B )

1

first plate

2

substrate plate

3

embossing tool

4

insertion movement

5

stroke

6

insertion movement

7

thermoplastic component

8th

component

9

Workpiece segments

10

Through opening

11

removal movement

12

ejection movement

13

insert structure

14

Ringzuganker

15

drilling

16

recess

17

stamp

Claims (8)

Process for the production of through-openings in thermoplastic components, comprising the following process steps: a) surface application of a first thermoplastic sheet ( 1 ) having a first softening temperature T1 on a substrate plate ( 2 ), b) impressing a tool tempered with a temperature above T1 ( 3 ) in the first thermoplastic plate, in which structures ( 6 ) with structural heights H1, c) lifting of the tool, d) placing a thermoplastic workpiece ( 8th ) with a second softening temperature T2 smaller T1 and with a thickness D2 smaller H1 to the previously cooled under T2 structures, e) re-impressing the tempered with a temperature T2 lower tool to form through holes through the workpiece into the structures, where punched workpiece segments ( 9 ) of the workpiece with the tool are pressed into recesses of the structures, f) lifting the tool ( 3 ) of the workpiece ( 8th ) and g) removal of the thermoplastic workpiece ( 8th ) with the passage openings. Method according to Claim 1, comprising the following downstream method steps: h) Removal of the punched-out workpiece segments ( 9 ) from the structures ( 6 ) and i) repeating steps d) to h) once or several times without replacing the first thermoplastic plate ( 1 ) with the structures ( 6 ) and each using a different workpiece ( 8th ) at each repetition. Method according to claim 2, wherein the removal of the workpiece segments ( 9 ) from the structures ( 6 ) by compressed air or by melting or fusing the workpiece segments to a solid. Process according to Claim 3, in which the solid is identified by stamps ( 17 ) or by an intermediate layer between the thermoplastic plate ( 1 ) and the tool ( 3 ) is formed. Method according to one of the preceding claims 1 to 4, wherein the workpiece ( 8th Polycarbonate (PC), polysulfone (PSU), polymethyl methacrylate (PMMA), cycloolefin copolymer (COC) or polyoxymethylene (POM) and the first plate ( 1 ) consists of polysulfone (PSU). Method according to one of the preceding claims 1 to 4, wherein the workpiece ( 8th ) of a polysulfone (PSU), polycarbonate (PC), polymethyl methacrylate (PMMA) or cycloolefin copolymer (COC) and the first plate ( 1 ) consists of polyetheretherketone (PEEK) or liquid crystalline polymers (LCP). Method according to one of the preceding claims, wherein the workpiece ( 8th ) has a flat surface in the region of the through openings on both sides. Method according to one of the preceding claims, wherein the workpiece ( 8th ) is a plate or foil-shaped component.